A Three Dimensional Finite Element Analysis of Delamination Growth in Composite Laminates. I. The Energy Methods and Case-Study Problems.

Abstract : This report presents in detail the application of an energy method to describe a class of delamination growth problems found in polymer-based composite laminates. The energy method is derived from the general concept of the classification fracture mechanics. When used judiciously and with proper interpretation of the physical factors pertinent to the crack growth process at the lamina(ply) level, the method provides an analytical simulation for the delamination process in laminates subjected to monotonic loading and/or cyclic loading, both in tension and in compression. Case studies involving one-dimensional growth (e.g. uniform free edge delamination) and two-dimensional delamination growth (contour delamination) have been performed along with laboratory tests using laminates made of AS-3501-06 graphite-epoxy system. Excellent correlation between experimental and predicted results has been achieved. (Author)